Influence of liposomal local anesthetics on platelet aggregation in vitro

We assessed the effect of local anesthetics (LA) from different families such as esters (benzocaine), linear aminoamides (lidocaine) and cyclic aminoamides (bupivacaine) on the platelet aggregation induced by ADP. Liposomal formulations of the three LA, prepared with egg phosphatidylcholine:cholesterol alpha-tocopherol, were also tested. The three LA were able to inhibit platelet aggregation induced by ADP, in the following order: bupivacaine > lidocaine > benzocaine. After encapsulation into liposomes the inhibitory effect increased for all anesthetics studied, showing that aggregation tests could be used to assess the toxicity of new drug formulations.     

Candidemia by Species of the Candida parapsilosis Complex in Children’s Hospital: Prevalence, Biofilm Production and Antifungal Susceptibility

Opportunistic infections are an increasingly common problem in hospitals, and the yeast Candida parapsilosis has emerged as an important nosocomial pathogen. The aims of this study were to determine and compare (i) the prevalence rate among C. parapsilosis complex organisms isolated from blood in a public children’s hospital in São Paulo state, (ii) the ability of the complex C. parapsilosis species identified to produce biofilm and (iii) the antifungal susceptibility profiles. Forty-nine (49) specimens of isolated blood yeast were analyzed, previously identified as C. parapsilosis by conventional methods. After the molecular analysis, the isolates were characterized as C. parapsilosis sensu stricto (83.7 %), C. orthopsilosis (10.2 %) and C. metapsilosis (6.1 %). All species were able to form biofilm. The species with the highest biofilm production was C. parapsilosis sensu stricto, followed by C. orthopsilosis and further by C. metapsilosis. All of the strains have demonstrated similar susceptibility to fluconazole, caspofungin, voriconazole, cetoconazole and 5-flucytosine. Only one strain of C. parapsilosis was resistant to amphotericin B. Regarding itraconazole, 66.6 and 43.9 % isolates of C. metapsilosis and C. parapsilosis, respectively, have demonstrated to be susceptible dose-dependent, with one isolate of the latter species resistant to the drug. Candida parapsilosis sensu stricto has demonstrated to be the less susceptible, mainly to amphotericin B, caspofungin and “azoles” such as fluconazole. Therefore, C. metapsilosis and C. orthopsilosis are still involved in a restricted number of infections, but these data have become essential for there are very few studies of these species in Latin America.     

An enhanced monomeric blue fluorescent protein with the high chemical stability of the chromophore

Commonly used monomeric blue fluorescent proteins suffer from moderate brightness. The brightest of them, mTagBFP, has a notably low chemical stability over time. Prolonged incubation of mTagBFP leads to its transition from a blue fluorescent state with absorbance at 401 nm to a non-fluorescent state with absorbance at 330 nm. Here, we have determined the chemical structure of the degraded product of the blue mTagBFP-like chromophore. On the basis of mTagBFP we have developed an improved variant, named mTagBFP2. mTagBFP2 exhibits 2-fold greater chemical stability and substantially higher brightness in live cells than mTagBFP. mTagBFP2 is also 1.2-fold and 1.7-fold more photostable than mTagBFP in widefield and confocal microscopy setups, respectively. mTagBFP2 maintains all other beneficial properties of the parental mTagBFP including the high pH stability and fast chromophore formation. The enhanced photostability and chromophore chemical stability of mTagBFP2 make it a superior protein tag. mTagBFP2 performs well in the numerous protein fusions and surpasses mTagBFP as a donor in Förster resonance energy transfer with several green fluorescent protein acceptors.     

Ecological Genetics of Mpi and Gpi Polymorphisms in the Acorn Barnacle and the Spatial Scale of Neutral and Non-neutral Variation

Different allozyme genotypes at the mannose phosphate isomerase(Mpi) locus in the northern acorn barnacle (Semibalanus balanoides)show a strong association with distinct intertidal microhabitats.In estuaries along the Maine Coast, the FF homozygote has higherfitness in exposed, high-tide level microhabitats while theSS homozygote has higher fitness under algal cover or at low-tidemicrohabitats. These patterns are consistent with a Levene (1953)model of balancing selection. In these same samples, polymorphismsat the glucose phosphate isomerase locus (Gpi) and mitochondrialDNA (mtDNA) show no fitness differences among microhabitats,providing intra-genomic controls supporting selection at ornear Mpi. Here we report a similar analysis of genotype-by-microhabitatassociations at sites in Narragansett Bay, Rhode Island, closeto the southern range limit of S. balanoides. Genotype zonationat Mpi between high- and low-tide microhabitats is significantlydifferent between Maine and Narragansett Bay due to oppositezonation patterns for the SF and FF genotypes. Enzyme activitydata are consistent with this "reverse" zonation. At Gpi, thereis significant microhabitat zonation in Narragansett Bay, whilethis locus behaves as a neutral marker in Maine. Mt DNA showsno significant microhabitat zonation in either Rhode Islandor Maine. The Mpi data suggest that Levene-type selection foralternative genotypes in alternative habitats may operate atscales of both 10's of meters and 100's of kilometers. The Gpidata show how an apparently neutral locus can exhibit non-neutralvariation under different environmental conditions. We arguethat both Mpi and Gpi provide important genetic variation foradaptation to environmental heterogeneity that is recruitedunder distinct conditions of stress and carbohydrate substrateavailability.     

Mutations in methylenetetrahydrofolate reductase and in cysthationine beta synthase: is there a link to homocysteine levels in peripheral arterial disease?

Peripheral arterial disease (PAD) is an atherosclerotic disturbance characterized by a progressive obstruction of lower limb arteries. Many risk factors associated with PAD development have being reported in the literature. The present study aimed to investigate whether mutations in the methylenetetrahydrofolate reductase (MTHFR) or in the cystathionine beta synthase (CBS) genes are associated with higher levels of homocysteine and the risk of PAD in patients from Brazil. This study analyzed 39 patients with PAD and 32 without PAD in whom risk factors and C677T mutations in the MTHFR gene and both 844ins68 and T833C mutations in the CBS gene were investigated. Although higher levels of homocysteine could be observed in patients with PAD compared to controls, no association between the increase of homocysteine and the frequency of C677T, 844ins68, and T833C mutations could be observed. The results suggest that these mutations do not appear to be related to either homocysteine levels or the development of the disease. However, hyperhomocysteinemia and smoking are important factors in PAD development.     

Patient and observer reported outcome measures to evaluate health-related quality of life in inherited metabolic diseases: a scoping review

Background

Health-related Quality of Life (HrQoL) is a multidimensional measure, which has gained clinical and social relevance. Implementation of a patient-centred approach to both clinical research and care settings, has increased the recognition of patient and/or observer reported outcome measures (PROMs or ObsROMs) as informative and reliable tools for HrQoL assessment. Inherited Metabolic Diseases (IMDs) are a group of heterogeneous conditions with phenotypes ranging from mild to severe and mostly lacking effective therapies. Consequently, HrQoL evaluation is particularly relevant.

Objectives

We aimed to: (1) identify patient and/or caregiver-reported HrQoL instruments used among IMDs; (2) identify the main results of the application of each HrQoL tool and (3) evaluate the main limitations of HrQoL instruments and study design/methodology in IMDs.

Methods

A scoping review was conducted using methods outlined by Arksey and O’Malley. Additionally, we critically analysed each article to identify the HrQoL study drawbacks.

Results

Of the 1954 studies identified, 131 addressed HrQoL of IMDs patients using PROMs and/or ObsROMs, both in observational or interventional studies. In total, we identified 32 HrQoL instruments destined to self- or proxy-completion; only 2% were disease-specific. Multiple tools (both generic and disease-specific) proved to be responsive to changes in HrQoL; the SF-36 and PedsQL questionnaires were the most frequently used in the adult and pediatric populations, respectively. Furthermore, proxy data often demonstrated to be a reliable approach complementing self-reported HrQoL scores. Nevertheless, numerous limitations were identified especially due to the rarity of these conditions.

Conclusions

HrQoL is still not frequently assessed in IMDs. However, our results show successful examples of the use of patient-reported HrQoL instruments in this field. The importance of HrQoL measurement for clinical research and therapy development, incites to further research in HrQoL PROMs’ and ObsROMs’ creation and validation in IMDs.

     

Structure of the bundle-forming pilus from enteropathogenic Escherichia coli

Bundle-forming pili (BFP) are essential for the full virulence of enteropathogenic Escherichia coli (EPEC) because they are required for localized adherence to epithelial cells and auto-aggregation. We report the high resolution structure of bundlin, the monomer of BFP, solved by NMR. The structure reveals a new variation in the topology of type IVb pilins with significant differences in the composition and relative orientation of elements of secondary structure. In addition, the structural parameters of native BFP filaments were determined by electron microscopy after negative staining. The solution structure of bundlin was assembled according to these helical parameters to provide a plausible atomic resolution model for the BFP filament. We show that EPEC and Vibriocholerae type IVb pili display distinct differences in their monomer subunits consistent with data showing that bundlin and TcpA cannot complement each other, but assemble into filaments with similar helical organization.     

Anti-inflammatory effects of tocopherol metabolites

Our objective was to assess the anti-inflammatory effects of alpha-tocopherol, gamma-tocopherol, and their metabolites 2,5,7,8-tetramethyl-2-(beta-carboxyethyl)-6-hydroxychroman (alpha-CEHC) and 2,7,8-trimethyl-2-(beta-carboxyethyl)-6-hydroxychroman (gamma-CEHC) in defined cell culture systems. Rat aortic endothelial cells and mouse microglial cultures were treated with tumor necrosis factor TNFalpha or bacterial lipopolysaccharide (LPS) and nitrite and prostaglandin E(2) (PGE(2)) were measured. alpha-CEHC suppressed TNFalpha-stimulated nitrite production in both cell types, whereas both CEHC derivatives inhibited LPS-stimulated microglial nitrite efflux. Both alpha-CEHC and gamma-CEHC inhibited microglial PGE(2) production, but neither alpha- nor gamma-tocopherol was effective at inhibiting cytokine-stimulated inflammatory processes. These results show that the anti-inflammatory effects of tocopherols are highly cell type-, stimulus-, and endpoint-dependent.     

Brucella abortus inhibits IFN-γ-induced FcγRI expression and FcγRI-restricted phagocytosis via toll-like receptor 2 on human monocytes/macrophages

The strategies that allow Brucella abortus to persist for years inside macrophages subverting host immune responses are not completely understood. Immunity against this bacterium relies on the capacity of IFN-γ to activate macrophages, endowing them with the ability to destroy intracellular bacteria. We report here that infection with B. abortus down-modulates the expression of the type I receptor for the Fc portion of IgG (FcγRI, CD64) and FcγRI-restricted phagocytosis regulated by IFN-γ in human monocytes/macrophages. Both phenomena were not dependent on bacterial viability, since they were also induced by heat-killed B. abortus (HKBA), suggesting that they were elicited by a structural bacterial component. Accordingly, a prototypical B. abortus lipoprotein (L-Omp19), but not its unlipidated form, inhibited both CD64 expression and FcγRI-restricted phagocytosis regulated by IFN-γ. Moreover, a synthetic lipohexapeptide that mimics the structure of the protein lipid moiety also inhibited CD64 expression, indicating that any Brucella lipoprotein could down-modulate CD64 expression and FcγRI-restricted phagocytosis. Pre-incubation of monocytes/macrophages with anti-TLR2 mAb blocked the inhibition of the CD64 expression mediated by HKBA and L-Omp19. These results, together with our previous observations establish that B. abortus utilizes its lipoproteins to inhibit the monocytes/macrophages activation mediated by IFN-γ and to subvert host immunonological responses.     

Evaluation of predatory mite (Acari: Phytoseiidae) releases to suppress spruce spider mites, Oligonychus ununguis (Acari: Tetranychidae), on juniper

A laboratory trial evaluated four phytoseiid species for their potential as biological control agents of spruce spider mite, Oligonychus ununguis (Jacobi) (Acari: Tetranychidae). An augmentative biological control approach, using the predatory mites Neoseiulus fallacis Garman and Galendromus occidentalis Nesbitt (Acari: Phytoseiidae), was evaluated for reducing pest mite densities and injury, and economic costs on Juniperus chinensis 'Sargentii' A. Henry (Cupressaceae) in an outdoor nursery. Sequential releases of predator species, individually and in combination, were tested and compared with two commonly used miticides, a low-toxicity miticide, horticultural oil, and a conventional miticide, hexythiazox. Timing of treatments was based on grower-determined need, and predator release rates were based on guidelines in literature received from producers of beneficial organisms. Predator releases were more expensive and provided less effective suppression of spruce spider mites, resulting in greater spider mite injury to plants, compared with conventional pesticides. However, spider mite damage to plants did not differ in an economically meaningful way between treatments. Unsatisfactory levels of control seem related to under estimations of actual spider mite abundance based on grower perceptions and the beat sampling technique used to estimate predator release rates. These data suggest that when initial populations of spruce spider mite are high, it is unlikely that sequential releases of predator species, individually or in combination, will suppress spider mite populations. In this trial, augmentative biological control control was 2.5-7 times more expensive than chemical controls.